Detecting dead users

[imperium2335]

Hi,

I know there are the event handlers onBeforeUnload and onunload, which work great 90% of the time.

But what would happen if a user who was in the system had a power cut? Would it then be down to the database that stores who is logged in to go through logging users out who havent done anything for a while?

Or could you use the PHP function 'exec' to ping the users IP address and if there is no response, log them off?

[Kor]

You may use a server-side session cookie which expires when the user leaves the site. Should work even if the system has a power cut.

[imperium2335]

Would my way work though? As the CGI stuff looks very complicated :/

[Kor]

Would my way work though? As the CGI stuff looks very complicated :/

Not more complicated than a client-side solution. But most of the time better:

http://www.tizag.com/phpT/phpsessions.php

[imperium2335]

So PHP would destroy a session if a user had a powercut or otherwise left the site? I know abit about these so I could use them, but I thought they persisted for a while after the user vanished?